A vehicle drivetrain component such as a transmission or differential, for example, may include a housing defining a cavity in which a set of gears and/or other movable component may be disposed. The housing may include a fill-hole through which a lubricant or other fluid may be poured into the cavity to lubricate and/or cool the gears and/or other movable components. A threaded plug is typically provided that removably engages and seals the fill-hole.